1. Field of the Invention
This invention relates generally to local area networks (LAN's), and more particularly to the remote wake-up of components connected to a local area network.
2. Description of the Related Art
Communication between multiple users across vast distances via a network has become almost a necessity in today's global marketplace. A Local Area Network (LAN) is a specific type of network which can support peer-to-peer communication over distances of tens of meters to several kilometers. A specific type of LAN is the ethernet, where information from multiple users travels through the network by use of a system bus in the form of discrete packets containing a number of pieces of information. A typical information packet contains a series of fields: a Destination Address Field; a Source Address Field; a Length Field; a Data Field where the user information is present and, in some cases, an error checking field.
Presently, there is a trend, due to the increasing use of lap top and other portable computers which operate on battery power for manufacturers to develop systems that have power conservation features or that can operate in a low power mode. Due to the increasing consumer demand for low power operation capability, the ability to wake-up a remote device in the SLEEP (low power) mode without the use of the Managed Processing Unit (CPU) or other Power Management circuitry which requires a lot of power and decreases battery life is becoming increasingly important to manufacturers. For a device that is in a low power mode, there is no simple and efficient way to determine how information packets that are received by the device through the network should be processed. In present systems, the CPU would have to be activated to process the incoming information to see if the entire device should be activated. This requires the use of a lot of extra hardware which uses a lot of energy which, in turn, means a shorter battery life. Also, if there is a mistake in the Destination Address, the information packet sent may be received by a subsystem, i.e. input/output (I/O) interface, that should not receive the information packet.
Thus, the ability to be able to wake-up a device in the low power mode and to transmit and process information quickly and accurately which is transmitted through a LAN is of importance to both manufacturers and consumers alike.